Figure of speech. Professor MacHugh says that "The
Roman, like the Englishman who follows in his footsteps,
brought to every new shore on which he set his foot (on our
shore he never set it) only his cloacal obsession." His
observation that conquering Roman armies never came to Ireland
(though English ones certainly did) is not merely contained
within parentheses. Its syntax fulfills the rhetorical concept
of parenthesis––inserting into a sentence a thought
that interrupts its grammatical flow.
Parenthesis (from Greek para- = beside + en- =
in + tithenai = to put, so "putting in beside")
originally referred not to the now-familiar punctuation marks
but to the action that they signal: interrupting a sentence to
insert a more or less independent aside, whether for
clarification or some other purpose. In The Garden of
Eloquence, Henry Peacham emphasizes both the
interruption and the fact that the rest of the sentence could
stand on its own syntactically if the intruding element were
removed: "Parenthesis is a form of speech which setteth a
sentence a sunder by the interposition of another...yet being
taken away, it leaveth the same speech perfect enough."
Today syntactically independent interpolations are usually
set off by parentheses or dashes, while ones that can be
grammatically incorporated with a conjunction or an adverb may
require only commas. These diversions of syntactic flow can be
quite effective at extending and deepening the thought
process, but they do distract from the clear articulation of
main points. Shakespeare, ever alert to both the uses and
abuses of rhetorical figures, conceived the garrulous old
Polonius as someone whose train of thought lives in constant
peril of being derailed by parenthetical reflections. Gideon
Burton (rhetoric.byu.edu) cites this example (there are many
others) of his inordinate fondness for parentheses
within parentheses:
But what might you think,
When I had seen this hot love on the wing—
As I perceiv'd it (I must tell you that)
Before my daughter told me—what might you,
Or my dear Majesty your queen here, think...?
(Hamlet 2.2.131-35)
Here the piling of parentheses, dashes, and commas on
top of one another emphasizes just how many burgeoning
syntactic diversions are involved. In comparison MacHugh's
parenthesis is pristine, virginal.
